r - 如何使用字符值连接/合并两个表？

Question

我想根据名字、姓氏和年份组合两个表，并创建一个新的二进制变量，指示表 1 中的行是否存在于第二个表中。

第一张表是一个赛季NBA球员的一些属性的面板数据集:

   firstname<-c("Michael","Michael","Michael","Magic","Magic","Magic","Larry","Larry")
   lastname<-c("Jordan","Jordan","Jordan","Johnson","Johnson","Johnson","Bird","Bird")
   year<-c("1991","1992","1993","1991","1992","1993","1992","1992")

   season<-data.frame(firstname,lastname,year)


    firstname   lastname        year
  1 Michael      Jordan         1991
  2 Michael      Jordan         1992
  3 Michael      Jordan         1993
  4 Magic        Johnson        1991
  5 Magic        Johnson        1992
  6 Magic        Johnson        1993
  7 Larry        Bird           1992
  8 Larry        Bird           1992

第二个data.frame是入选全明星赛的NBA球员部分属性的面板数据集:

   firstname<-c("Michael","Michael","Michael","Magic","Magic","Magic")
   lastname<-c("Jordan","Jordan","Jordan","Johnson","Johnson","Johnson")
   year<-c("1991","1992","1993","1991","1992","1993")

    ALLSTARS<-data.frame(firstname,lastname,year)



     firstname  lastname    year
  1 Michael     Jordan    1991
  2 Michael     Jordan    1992
  3 Michael     Jordan    1993
  4 Magic       Johnson   1991
  5 Magic       Johnson   1992
  6 Magic       Johnson   1993

我想要的结果如下:

  firstname lastname    year    allstars

   1    Michael Jordan  1991    1
   2    Michael Jordan  1992    1
   3    Michael Jordan  1993    1
   4    Magic   Johnson 1991    1
   5    Magic   Johnson 1992    1
   6    Magic   Johnson 1993    1
   7    Larry   Bird    1992    0
   8    Larry   Bird    1992    0

我尝试使用左连接。但不确定这是否有意义:

    test<-join(season, ALLSTARS, by =c("lastname","firstname","year") , type = "left", match = "all")

Answer 1

这是一个使用 data.table 的简单解决方案二元连接允许您在连接时通过引用更新列

library(data.table)
setkey(setDT(season), firstname, lastname, year)[ALLSTARS, allstars := 1L]
season
#    firstname lastname year allstars
# 1:     Larry     Bird 1992       NA
# 2:     Larry     Bird 1992       NA
# 3:     Magic  Johnson 1991        1
# 4:     Magic  Johnson 1992        1
# 5:     Magic  Johnson 1993        1
# 6:   Michael   Jordan 1991        1
# 7:   Michael   Jordan 1992        1
# 8:   Michael   Jordan 1993        1

或使用 dplyr

library(dplyr)
ALLSTARS %>% 
  mutate(allstars = 1L) %>%
  right_join(., season)
#   firstname lastname year allstars
# 1   Michael   Jordan 1991        1
# 2   Michael   Jordan 1992        1
# 3   Michael   Jordan 1993        1
# 4     Magic  Johnson 1991        1
# 5     Magic  Johnson 1992        1
# 6     Magic  Johnson 1993        1
# 7     Larry     Bird 1992       NA
# 8     Larry     Bird 1992       NA